Railway-track circuit apparatus



April 3, 1928.

H. S. YOUNG RAILWAY TRACK CIRCUIT APPARATUS Filed Oct. '7. 1926 INVENTOR Patented Apr. 3,1928.

- UNITED STATES- oi-"r ce.

HENRY 's. YOUNG, or ,WILKINSVBURG, 'rnnfus nvenm, ASSIGNOR TO .THE UNION swrrcrra SIGNAL COMPANY, OF swissvALn, rnNnsrLv nrii, A con'roaa'rron or PENNSYLVANIA.

RAILWAY-TRACK CIRCUIT APPARATUS;

Application'filed October 7, 1926. Serial No. 140,Q09. Y

My invention relates to railway track circuit apparatua'andhas for an obJect the provision of means for improving the operation of track relays. I Y I will describe three forms of apparatus embodying my invention, and will then point out the novelfeatures thereof in claims.

Int-heaccompanying drawing, Fig. 1 1s a diagrammatic view, showing one form of apparatus embodying my invention- Figs."

2 and 3 are views showing modifications of the apparatus shown in Fig. 1 and bodying my invention. I

Similar reference characters refer to similar parts in each of the several views.

Referring first to "Fig. 1,' the reference characters 1 and 1 designate the track rails of a railway which are divided byinsulated joints 2 to form a track section A-'-B This section is provided with a track circuit comprising a source of current connected across the rails at one end and .a track relay R having a winding connected across the rails at theotherend. As here shown, the source of track circuit current is a track transformer '1 having its secondary 3 .connected across the rails through a' limiting reactance .8. and having its primary 4 constantly supplied with alternating current from a trans mission line 5. The relay R. comprises a winding- 6 connected across the rails-l and 1. and a secondwinding 7 constantly sup plied with alternating current from a'transformer L which in turn is energized from the transmission line 5.

Located at the transformer end B'of section AB is a floating relay F which is connected acrossthe track rails 1 and 1 so that this relay is normally energized. Interposed between the winding of relay F and the lower track rail 1 is an impedance Qwhich,

4 as here shown. is a resistance. When the relay F is closed. this impedance 9 is shunted by'a low resistance path including a front contact 10 of relay F. g I I I have observed that whenthe floating relay F is connected directly across the track rails in accordance with standard practice, and when a train is in the section moving toward the floating relay, this relay will open when the train reaches a certain point in' The train shunt may then bealso emthe track rails, and may therefore, allow the front contacts of thefioating relay to again close. As the train proceeds toward the floating. relay, the shunt resistance will again become lower, so that this relay Twill againiopen its frontcontacts. Thisaction of the. floating relay maybe-termed bobbing. When, however, the floating relay.

is connected with the rails in the manner shown in Fig. 1, the relay will remain open after it once opens, because the impedance 9 is then .eflective to materially reduce the amount of current supplied to the relay. Conversely, when a train is insection A-B moving away from the floating relay F, this relay will close when the train reachesa certain point in the section andwill thereafter remain closed even. though the resistance of the shunt created by the train may 'front contact 10 of the'floating relay F.

When contact 10 is closed, the amount of current supplied-to the winding of relay F is relatively large, and when this contact is open theamount of current supplied to the winding-of relay F is relatively small. and

so the operation ofthe apparatus shown in Fig. 2 is the same as that of the apparatus shownin Fig. 1. i 1 v j I Referring now toFig. 3, the section AB shown in this View is provided with a centerfed track circuit comprising a track transformer vT; located at the middle of the section and two track relays R, R located at the two ends of, the section, respectively. Wind ing 6 ofea'ch relay R is connected with the track rails, and winding 7 of each of these relays is constantly supplied with current y from an adjacent transformer L. In thisview an impedance 9 is connected in series with winding 7 of each relay R, and each impedance 9 is provided with a low resistance shunt which includes a front Contact 10 of the associated relay. Assuming that a train moving toward the left passes through section A-B, track relay R at the left-hand end of the section will open when-the train reaches a point a short distance to the right of transformer T, whereupon the amount of current supplied to the winding 7 of this relay will become materially reduced, so that the relay will remain open even it the shunt across the track rails due to the wheels and axles of the train mon'lcntarilyincreases in resistance. Similarly, when a train moving toward the right reaches a point a short dis tance to the left of transformer T, relay R at the right-hand end of the section will open and will thereafter remain open even though the resistance of the train shunt increases momentarily. 7

Obviously, the resistance 9 in Fig. 3 may be interposed between relay winding 6 and a track rail, as shown in Fig. 1.

'Although I have herein shown and described only three forms otapparatus embodying my invention, it is understood that various changes and modifications may be made therein within'the scope of the appended'claims without departingfrom the spirit and scope of my invention.

- Having thus described my invention, what I claim is 1. In combination, a section of railway track, a source of current connectedacross the rails of said section, a relay connected across the rails of said section through an impedance, and a shunt around said impedance including afront contact of said relay.

2. In combination, a section of railway track, a track circuit for said section including a source of current connected across the rails at one end and a track relay connected across the rails at the other end, a floating relay having a winding connected across the rails of said section adjacent the first mentioned end through an impedance, and a shunt around said impedance including'a front contact of said floating relay.

3. In combination, a section of railway track, a track circuit for said section including a source of current connected across the rails'at one end and a track relay connected across the rails at the other end, a floating relay having a winding connected across the rails ofsaid section adjacent the first mentioned end an impedance included in series with a winding of said floating relay, and a shunt around said impedance including a front contact of said floating relay.

eague 4:. In. combination, a section of railway track, a source of current connected across the rails ot-said section, a'relay having-a winding connected across the rails of said section, an impedance in series with a winding of said relay, and a shunt around said.

impedance including a front contact of said relay. '7 i 5. In combination, a section of railway track, a source of current connected across the rails of said section, a relay having a winding connected across the rails of said section, an impedance connected in series with said source, and a shunt aroundsaid impedance including atront contact of said relay. j

6. In combination, a section of railway track, a source of current connected across the rails'oi said section,"a'relay having a winding connected across-the rails of said.

section, animpedance for limiting the amount of current received by said relay,

and a shunt around said impedance including a front contact of said relay.

7. In combination, a section of railway track, a track circuit torsaid section including' a source of current and a track relay, an impedance in series with a winding of said relay, and a shunt around said impedance including a front contact of said relay.

8. In combination, asection of railway track, a track circuit for said section including a source of current and a track relay, an impedance for limiting the amount of current received by said relay, and a shunt around said impedance including a front contact of said relay.

9. In combination, a section of railway track, a source oi: current connected across the' rails ot said section, a relay having a winding connected across the rails of said section, and means controlled by said relay tor'supplying a smaller amount of current to the relay when the relay is open than when amount of current thereto when the floating relay is open than when it is closed.

In testimony whereof I aifix my signature.

HENRY S. YOUNG. 

